S M AUTO PARTS SUCKS

So here's my story Ordered a part from S M AUTO once trying to order The consultant called via whatsapp Round about 5 times Request payment I made payment the same day and was assured 3 working days Even send me pictures of the part A week went past and no part received Nor any feedback from them Eventually got a reply after 10 days I requested my money back because they never delivered the part I was told a 20% would be deducted No part was given so now how can you deduct 20% I've given the details as to where it should be delivered to Today 2 weeks later still no reply I've called many times and up till now only received a message telling me consultant's are busy but will get back to me That was at 10 am this afternoon It's now 15:08 5 hours later and no reply Please help me